![]() | 1 | initial version |
sage: F = GF(127^2)
sage: E = EllipticCurve(F, [1,0])
sage: i = E.automorphisms()[-1]
sage: assert i^2 == -1
sage: endo = 2 * i
sage: assert endo in End(E)
sage: assert endo^2 == -4
sage: endo
Composite morphism of degree 4 = 1*4:
From: Elliptic Curve defined by y^2 = x^3 + x over Finite Field in z2 of size 127^2
To: Elliptic Curve defined by y^2 = x^3 + x over Finite Field in z2 of size 127^2